CSS is your bridge to low cost high quality FRP composite products

Composite Bladder Inflation Molding (BIM) Support

"Tackle complex hollow composite structures with confidence ..."

CSS has more than 30 years of experience supporting the design and manufacture of complex hollow FRP composite structures produced with Bladder Inflation Molding (BIM). Examples of common and more challenging BIM part geometries include:

As part of our Composite Product Development services, CSS helps Clients design and manufacture bladder molded prototypes from prepreg layups or resin infused preforms.   Our services include custom bladder development, custom air fitting design, and BIM tooling design.   And though CSS does not manufacture or sell bladders, we can recommend the best off-the-shelf bladder for straight forward bladder molding applications.

CSS also supports the development of in-house bladder molding production capability via our Composite Production Support services or, in the case of medium to high volume application, overseas production and procurement of bladder molded production parts and value added assemblies (Overseas Composite Production).

Bladder Inflation Molding Advantages/Benefits ...

Prepreg Versus Resin Infused Preforms ...

BIM parts may be fabricated from hot melt prepreg preforms or dry fiber preforms infused with resin during the bladder molding process.   The bladder's role and bladder inflation pressure differ depending on the preform type.

In the case of prepreg bladders, the bladder's role is to consolidate the prepreg layers and maintain the consolidated part shape until the resin matrix cures.   Higher internal bladder pressures are typically employed to generate resin flow, drive entrapped air out of the layup, and consolidate the fiber reinforced prepreg layers against the tool surface.

Prepreg Bladder Inflation Molding


A resin infusion bladder, on the other hand, is typically inflated with less pressure to avoid collapsing the dry fiber preform and shutting off essential resin flow channels. The resin infusion bladder's role is that of a soft tool surface during impregnation and to maintain wetted preform shape as the resin gels/cures.

Resin Infusion Bladder Inflation Molding


Bladder material selection is driven by part geometry, processing temperature, reusability requirements, and cost.   Common bladder materials include latex rubber, polyamides (nylon), silicone rubber, and polyetheretherketone (PEEK).

Bladder Inflation Molding Case Studies ...


Resin Infused Composite Spool Composite Bent Paddle Shaft Curved Composite Tent Poles Composite Stroller Frame Member


Please Contact Us to learn more about CSS Bladder Molding Support services or to discuss your FRP composite program needs.